This invention relates to a roofing membrane or what is commonly referred to as a roofing felt. Commonly used roofing felt is made in sheets which are about three feet wide and are rolled into rolls of about 80 pounds weight. The material is used over the furred roof surface and beneath the tile or shingles which are applied upon a roof.
The length of sheet is essentially determined by the amount of material which makes up an 80 lb. weight. That is, 80 pounds appears to be an historically, arbitrarily, selected weight for a roll of roofing material which can be handled by roofers in lifting the rolls upon the roofs of the buildings and working with them.
Typical roofing felt has an expected life of about twenty years. That is, a roof on a residential dwelling is generally considered to have a twenty year life, approximately, after which it must be replaced or repaired substantially.
The invention herein relates to an improved roofing felt or roofing membrane which is much lighter in weight, per square foot, than conventional roofing felt so that an 80 pound roll contains considerably more sheet material than common roofing felt. In addition, the material is anticipated to have a life expectancy which is considerably greater than that of common roofing felt.